code: def test_batch_tensors_returns_single_value(self):
      value = True
      fields = [FlagField(value) for _ in range(5)]
      values = [field.as_tensor({}) for field in fields]
      batched_value = fields[0].batch_tensors(values)
      assert batched_value == value
  
file_path: allennlp/tests/data/fields/flag_field_test.py
imports: import pytest
  from allennlp.common.testing.test_case import AllenNlpTestCase
  from allennlp.data.fields import FlagField
label_desc: Use image node_id 5 for calling the TestFlagField obj's underlying member method code with example usage: obj.test_batch_tensors_returns_single_value() without return types